Kansas Republican Sen. Pat Roberts is setting his sights on raising $5 million in his bid to return to Washington for another six-year term, even with no opposition on the immediate horizon.

Roberts plans to campaign aggressively statewide over the next 18 months to retain the seat he first won in 1996.

“I never have and never will take anything for granted,” said Roberts, 77. “I think I can continue to make a difference for Kansas and the country.

“We've just begun to fight.”

The odds – and $1.2 million in cash on hand – are in Roberts' favor. No Democrat has held a U.S. Senate seat from Kansas since 1932. Roberts won re-election in 2008 by defeating Democrat Jim Slattery by a 60 to 36 margin. Slattery is a former 2nd District congressman in eastern Kansas.

No Democrat has emerged as a challenger to Roberts, though state party executive director Jason Perkey said Friday that a number of potential candidates were considering a run at Roberts.

“We're still in the recruitment phase,” Perkey said.

Kansas State University political scientist Joe Aistrup said the bigger threat to Roberts would be a challenge from the far right wing of the GOP, which appears less likely than previously thought.

“He's done a lot within the last four years to enamor himself to the people on the right,” Aistrup said. “It would have to be a big name like (Secretary of State) Kris Kobach, for example, that it would take to knock him off.”

If Roberts doesn't have a primary next summer it would be a stark contrast to the 2010 race between Republicans Jerry Moran and Todd Tiahrt who duked it out to replace Sam Brownback, who retired to run for governor.

Aistrup said Democrats had a “thin bench” and few potential candidates who could give Roberts a stiff challenge.

“Kansas is going to be a red state for a long time,” he said.

Roberts spent 16 years in the U.S. House, representing the state's 1st District of predominantly western Kansas. He has served in several high-profile committee positions, including a key Senate intelligence committee in the early 2000s when Republicans controlled the Senate.

Perkey thinks Roberts' tenure in Washington could work against him with voters, as well as his recent vote against the new farm bill passed by the Senate.

“I think we've got some strong issues to run on this cycle,” Perkey said. “We think Kansans deserve someone who represents them and not just comes back to pick up a donor check.”

Roberts defends his vote on the farm bill, saying it wasn't the best deal for Kansas agriculture and he hopes it gets improved before becoming law.

Roberts said the bill he helped pass in 2012 was a better bill for Kansas farmers and ranchers, while curbing federal spending. He's hoping for quick passage of a five-year plan that will give the agriculture community more certainty and independence.

“What I really worry about is that the farmers could be planting for the government and not the markets,” he said.

Perkey said Democrats will make the case to voters that Kansas has taken a turn to the right politically under Brownback to the benefit of wealthy residents and corporations and detriment of families.

“Unfortunately, Sen. Roberts is in the same mold,” Perkey said.

But Aistrup said Democrats will have a harder time convincing voters to give them a serious look based on the recent spate of scandals coming under President Barack Obama's watch.

“The only way Democrats are going to win is if there is a strong tail wind. And the economy isn't as strong that they will get a push from it,” Aistrup said.